Loud-speaker unit



April 19 1927. 1,625,148

G. R. PENN LOUD SPEAKER UNIT Filed Sept. 50. 1926 2 Sheets-Sheet 1 66 01:9 GRM 3140c 5 la s-WI April 19 1927.

(5, R. PENN LOUD SPEAKER UNIT Filed Sept. 30. 1926 2 Sheets-Sheet 2 Patented Apr. 19, 1927.

UNITED STATES 1,625,148 PATENT OFFICE.

GEORGE E. PENN, 01! NEW YORK, N. Y., ASSIGNOR '10 S. B. PENN MPG. 00., OF NEW YORK, N- Y.

Loon-arm Imrr.

Application filed September 30, 1926. Serial Ilo. 138,695.

This invention relates to a loud speaker unit designed primarily for use with a cone diaphragm, one of the objects oi the invention being to provide a unit so constructed 6 as to eliminate unnecessary vibrations and improve both the quality and volume of the tone.

A further object is to provide a unit the parts of which can be rapidly assembled in 10 quantit production.

A sti 1 further object is to provide simple and efficient means for regulating the volume, the said means being so mounted and constructed that danger of development of 1| loose connections is practicall eliminated with the result that the desire tone can be maintained indefinitely.

Another object is to provide an adjustable support for the unit, thereby allowing the 50 same to be assembled with cone diaphragms of different sizes.

A further object is to provide a unit of this character which can be sold for installation by the purchaser in a cone speaker nl of home-made construction.

With the foregoing and other objects in view which will appear as the description proceeds, the invention resides in the combination and arrangement of parts and in 80 the details of construction, hereinafter described and claimed, it bein understood that changes in the precise em odiment of the invention herein disclosed may be made within the scope of what is claimed, without 35 de arting from the spiritof the invention.

11 the accompanying drawings the preferred form of the invention has been shown.

In said drawings,

Figure 1 IS a front elevation of the unit,

49 the cone diaphragm being removed.

Figure 2 1s a side elevation, a portion of the cone being shown in section.

Figure 3 is a section on line 3-3, Figure 1.

Figure 4 1s a rear elevation of the unit,

45 its supporting bracket being removed.

Figure 5 1s a top plan view of the unit.

Figure 6 is a. section on line 66, Figure 3.

. Fi re 7 is a front elevation of a slightly so moded form of unit.

Figure 8 is a section on line 8-8, Figure 7.

Referring to the figures by characters of reference 1 designates the back of the loud .5 speaker which can be in the form of a disk of any suitable construction. Arranged on one face of this disk are spacing strips 2 provided with terminal ears 3 and 4, the cars 4 being in contact with the back 1. An elongated bolt 5 is extended through the back and through the ears 3 and 4 of each strip 2, it being understood that the number of these bolts is equal to the number of the spacing strips. A nut (3 engages each bolt and is adapted to be adjusted against the adjacent ear 4, thereby to tightly clamp the base 1 between the head 7 of the bolt and the ear 3. Thus the strips 2 are mounted firmly relative to the base.

The threaded end portions of the bolts projecting beyond the ears 4 are each engaged by a pair of nuts 8 and mounted between and clamped by these nuts so as to be firmly supported by the bolts at desired distances from the back 1 are the terminals of a spider 9 formed preferably of insulating material and including a cross strip 10 and a central depending strip 11. A permanent magnet 12 is engaged at its center b a clip 13 which serves to hold it firmly to t e strip 11 of the spider and mounted on the terminals of the fixed magnet are alining pole pieces 14 each preferably formed of a flat piece of metal supporting the coil 15 of an electromagnet. The two coils are electricall connected as indicated at 16 while the ot er terminals of the coils extend to any suitable connections indicated at 17 to which are attached the ends of the cord 18 extending to the unit. These connections 17 are carried b a block 19 of suitable insulating materia referably of skeleton formation and which block is attached at its sides to the pole pieces 14 and to the terminals of the fixed magnet by bolts 20 extending through the block 19, the pole pieces, the terminals of the fixed magnet and the strip 10. Block 19 includes a bridge portion 21 which extends across the space between the terminals of the fixed magnet and 100 carried by this brid e portion is an abutment block 22 norma l contacting with the free end portions of t e pole pieces. Thus vibrationof the pole pieces during the operation of the unit is prevented and many 105 of the undesirable noises heretofore produced in units employing relatively thin pole pieces, are eliminated.

A sprin strip 23 extends transversely of the blocg 19 and is secured at its ends to 110 opposite side portions of this block. Extending outwardly from the middle portion of the spring strip is a sleeve 24 the outer end of which is interiorly screw threaded so as to receive a tubular screw plug 25 in which is mounted an adjusting screw 26 extending longitudinally within the plug. This adjusting screw has a head 27 by means of which it can be rotated readily and a set screw 28 extends into the plug for the purpose of binding on theadjusting screw 26 to hold it against accidental rotation.

Secured to the middle portion of the block 19 adjacent the bottom thereof is one end of a spring strip indicated at 29 and this strip is extended. through the block and thence close to and in lapped relation with the free end portions of the pole pieces 14. This spring strip constitutes the armature of the magnet and normally bears against one side of the pole pieces while the other side of the pole pieces normall engages the abutment block 22 as hereto are explained. A push rod 30, preferably in the form of a stiff wire, is fixedly attached to the armature at a point close to the ole pieces and. is mounted to slide within e sleeve 24 and the screw plug 25. Thus when the parts are properly assembled the rotation of adjusting screw 26 in one direction will result in pressure by said screw against rod 30 and consequent adjustment of the armature away from the pole pieces. The extent of vibration of the strip 23 and the parts carried thereby will depend upon the distance that the armature is adjusted away from the pole pieces. A diaphragm 31 preferably of cone-shape is detachably secured to the sleeve 24. its apex portion being preferably clamped between small disks 32 and 33 mounted on the screw plug and clamped firmly to the sleeve 24 by said plug.

It will be obvious that, as the armature vibrates, vibratory motion will be transmitted therefrom through the rod 30 to screw 26 and thence through sleeve 24 to spring stri 23. Thus the diaphragm will be vibrate By having the set screw 28 the parts can be held securely after adjustment so as not to work loose and cause inadvertent change in quality or volume of tone.

For the urpose of ada ting the unit to cone diap ragms of di erent sizes and shapes, the unit has been mounted on the bolts 5 as already explained, the nuts 8 serving to hold the spider 9 firml at a desired distance from the back 1. Obviously these nuts can be adjusted toward or from the strips 2 so as to locate the unit closer to or farther from the back according to the size of tone diaphragm employed. This mounting of the unit is es ecially desirable in cases where units are sol to customers who make their own cone diaphragms, it bein possible to use the same unit wlth cones 0 all sizes.

Instead of mounting the armature as already dcscribed, a slightly modified arrangement can be used as illustrated in Figures 7 and 8. In this form of device the insulating block 19' has a spring strip 34 secured at its ends to opposed portions of the block. The sleeve 24 is extended from the upper portion of the spring strip while a spacing sleeve 35 is extended in the opposite direction from the lower portion of the sprin strip and is fixedly attached thereto. One end of the spring armature 36 is attached to this spacing sleeve while the other end portion has a push rod 30' extending from it into the sleeve 24'. In all other respects this modified structure is the same as the one heretofore described. In other Words the modified arrangement differs from the preferred form by the provision of an arinature'supported solely by the spring strip carrying the diaphragm.

What is claimed is:

1. A loud speaker unit including a permanent magnet, pole pieces extending from the terminals thereof, coils mounted on the pole pieces, an armature close to but normally spaced from the pole pieces at one side, and an abutment normally engaging the opposite side of the pole pieces for limiting their movement under the pressure of the armature when attracted to the pole pieces.

2. A. loud speaker unit including a permanent magnet. flat pole pieces extending from the terminals thereof, electromagnet coils carried by the pole pieces, an abutment of non-conducting material normally contacting with one side of the pole pieces, an armature normally positioned adjacent but spaced from the other side of the pole pieces, a resiliently mounted diaphragm support, and means adjustably connected to said support for adjusting the armature away from the pole pieces.

3. A loud speaker unit including a permanent magnet, opposed alining pole pieces extending from the terminals thereof, electromagnet coils carried by the pole pieces, an armature close to but normally spaced from one side of the pole pieces, a resilient diaphragm supporting structure, an adjusting screw carried thereby, a thrust element for transmitting motion from the screw to the armature. and means for holding the screw against accidental rotation.

4. A loud speaker unit including a magnet having opposed alining pole pieces at the terminals thereof, eleetromagnet coils carried by the pole pieces, a resilient armature close to but normally spaced'from one side of the pole pieces, an abutment normally engaging the other side of the pole pieces, a diaphragm supporting structure, and an adjustable thrust connection between said structure and the armature.

5. A loud speaker unit including a magthe terminals "thereof, electromagnet coils carried by the fpole pieces, an armature normally spaced om and movable relative to one sideof the pole pieces, an abutment of non-conducting material normally engaging the other side of the pole pieces, a resilient diaphragm supporting structure, and an adjustable thrust connection between said structure and the armature.

6. The combination with a back and a diaphra m supported close to the back, of thread members fixedl connected to the back, a structure adjusts, 1y mounted thereon, a loud s eaker unit carried by said structure, an a connection between said unit and the diaphragm said diaphragm cooperating with the bac to house the unit and its supportim structure.

7. A loud speaker unit including a magnet having opposed alining pole pieces, electromagnet coils carried thereby, a block of insulating material bridging the magnet, an

abutment carried by the block normally engaging one side of the pole pieces, an armature close to but normally spaced from the other side of the pole pieces, a resilient strip upon the block, means carried thereby for engagin and supporting a diaphragm, a push ro extending from the armature, and an adjusting element carried by the diaphragm supporting means for actuating the push rod to adjust the armature away from the pole pieces.

In testimony that I claim the foregoing as my own, 1 have hereto nflixed my signature.

GEORGE R. PENN.

net having opposed alining pole pieces at the terminals thereof, electromagnet coils carried by the le pieces, an armature normally spaced rom and movable relative to one sideof the pole pieces, an abutment of non-conducting material normally engaging the other side of the pole pieces, a resilient diaphragm supporting structure, and an adjustable thrust connection between said structure and the armature.

(5. The combination with a back and a diaphra m supported close to the back, of thread members fixedl connected to the back, a structure adjusta ly mounted thereon, a loud seaker unit carried by said structure, an a connection between said unit and the diaphragm said diaphragm cooperating with the heel: to housethe unit and its supportin structure.

7. A 1011(1 speaker unit including a magnet having opposed alining pole pieces, electromagnet coils carried thereby, a block of insulating material bridging the magnet, an

ture.

GEORGE R. PENN.

CERTIFICATE OF CORRECTION.

Patent No. l, 625, 148.

Granted April 19, 1927, to

GEORGE R. PENN.

It is hereby certified that the name of the asaignee in the above numbered patent wae erroneously written and printed as "S. R. Penn Him; Co. whereas said name should have been written and printed as "G. R. Penn Mtg. 00.", as shown by the records of assignments in this office; and that the said Lettere Patent ehould be read with this correction therein that the same may conform to the record of the case in the PatentOttiee.

Signed and sealed this 24th day of May, A. D. 1927.

Seal.

M. J. Moore. Acting Commissioner of Patents.

CERTIFICATE OF CORRECTION.

Patent No. 1,625,148. Granted April 19, 1927, to

GEORGE R. PENN.

It in hereby certified that the name of the assignee in the above numbered patent was erroneously written and printed as "S. R. Penn Mfg Co. whereas said name should have been written and printed as "G. R. Penn Mfg. 00.", as shown by the records of assignments in this office; and that the said Lettera Patent ahould be read with this correction therein that the name may conform to the record of the one in the Patent Office.

Signed and sealed thia 24th day of May, A. D. 1927.

M. J. Moore, Seal. Acting Gommisaioner of Fatenii. 

